Conventional archery devices usually include a bow having two arms with a bowstring strung between the ends of the arms. The user grasps the bow and "draws" the bowstring with one hand while pushing the bow itself with the other hand. The term "drawing" in both crossbow and conventional archery technology can refer to moving the bowstring into a position to fire an arrow, and is applicable to a pushing as well as a pulling movement of the bowstring.
Drawing the bowstring tends to cause the arms to want move toward each other, creating tension therebetween. The amount of force necessary to draw a given bow is usually measured in pounds and is known as the "draw weight" of the bow. When the bowstring is released, energy is transferred through the bowstring and to the arrow which is propelled or "fired" toward a target.
One method of increasing the speed at which an arrow is propelled is to increase the stiffness of the bow arms. However, the user must be able to draw the bowstring. Thus, increasing the stiffness of the bow arms to create a very high draw weight bow may be useless if the user cannot draw it and hold the bow in the drawn position for a sufficient period of time to aim at the target. If the user is struggling with holding the bow string in the drawn position, his aim will be deleteriously affected.
Crossbow technology was developed to relieve the tension applied to the user's arms as encountered when using a conventional bow as discussed hereinabove. The stock of the crossbow holds the bowstring in the drawn position, allowing the user to aim without concern for manually holding and maintaining the draw weight. This technology has given rise to modern crossbows having draw weights of 150 pounds or more.
Trigger mechanisms, as known in the art, were developed in order to both hold the bow string in the drawn position, and to release the bowstring when the trigger is operated. Often, a bowstring catch is provided which holds the bowstring until the trigger is manipulated, which in turn rotates or otherwise moves a sear, releasing the bowstring catch and hence, the bowstring itself. When the bowstring is drawn and held in the drawn position by the trigger mechanism, the crossbow is said to be "cocked".
In order to draw the bowstring and cock the crossbow, the user must be strong enough to draw the full draw weight of the bow. Devices have been incorporated into crossbows to make this operation easier for the user. For example, it is known to provide a stirrup bracket mounted on one end of a crossbow. The user places the stirrup bracket onto the ground and places a foot into the bracket. By applying the user's body weight to the grounded bracket, the user can then pull back or "draw" the bowstring. For a crossbow having a very high draw weight, and for users having less strength than some others might have, this operation often proves difficult.
Manual crank winch devices are known to draw the bowstring of a crossbow. These devices are often cumbersome to connect and disconnect from the crossbow with each use. Moreover, they are usually large and difficult to use taking more time and effort than it is worth. Therefore, a need exists for a device which will draw the bowstring of a crossbow, which is easily connected to the crossbow, and which is simple to operate.